The invention relates to internal combustion engines and more particularly to two-stroke internal combustion engines. Still more particularly, the invention relates to exhaust systems for such engines, especially in outboard motors.
U.S. Pat. No. 5,101,626, which is assigned to the assignee hereof and which is incorporated herein by reference, discloses a two-stroke internal combustion engine including an exhaust gas discharge system which, for each cylinder, provides an outgoing positive acoustical pressure wave that arrives at the exhaust port of the previously fired cylinder prior to closure thereof and provides a returning negative acoustical pressure wave that travels in the exhaust system after substantial completion of the travel of the outgoing positive acoustical pressure wave and that arrives at the exhaust port of the originating cylinder prior to closure thereof.